This invention relates to landmine protection arrangements and in particular, to articles that are associated with the foot and leg of an animal or person which or who may be vulnerable to a landmine explosion.
There has been an historical approach to providing protection against landmines which has provided for deformable members arranged to take some of the blast and shock and deformable outer parts of boots and other protection elements in the belief that this would be most beneficial.
The problem of protecting a lower limb or limbs and other parts of the human or animal body from an exploding landmine is a very difficult one indeed.
The problem to which this invention is directed is to provide an approach which has for its purpose reducing damage to the said human or animal parts in the event that a landmine is triggered by that person or animal.
In one form of this invention there is proposed an item of footwear adapted to be worn by a person or animal which item includes a substantially non-deformable metal sheet adapted to be positioned below the foot of a wearer characterised in that the sheet of metal is aligned so that an outer side which is a side further from the instep of a potential user, is higher than the portion of the sheet closer to the in-step side so as to effect a redirection of any up-welling as a result of an exploding landmine to an outer side of the item of footwear when being worn.
In preference, the sheet is generally planar and is positioned to assume an inclined orientation generally within the range relative to the horizontal of from ten degrees to fifty degrees such that in the event of an up-welling of the results of a landmine explosion, both preceding shock and pressure waves and any following pressure wave is to some extent diverted to an outer side.
By making such a sheet so that it will be substantially non-deformable, means that there will then be effected a substantial diversion to a side of at least preliminary shock and pressure waves and in relation to any following pressure wave there will be a lessening of the upward pressure on the plate both by reason of the alignment of the sheet and its positioning, and in preference by reason of additional materials and packaging and venting.
In preference, the article further includes an outer shell which is also hard rather than soft so that it is adapted to deflect and direct any initial shock and pressure waves past the body elements of the user.
A footwear upper shape having an outer shell made from polycarbonate plastic is typical of a suitable material for this purpose.
A next problem however relates to further parts of the lower limb of the user and in accord with a preferred further feature of this invention, there is proposed a protective surround which is made from a hard material adapted to further deflect shock and pressure waves and which has a lower rim which is adapted to fit within a surrounding outer part of a boot portion of the arrangement.
In preference, the footwear item is generally in the form of a boot and will be referred to as this subsequently. Accordingly the boot is connected to the protective surround by an interconnecting connection which is however adapted to allow for pivotal movement between the boot and the upper protective surround.
Such a pivotal connection allows for relative movement of the foot with respect to the lower part of the leg, in other words allowing for ankle movement, and this then allows for more comfortable ability to walk using this apparatus under normal conditions.
However, by having the connection of the boot coupled to the protective surround, means that an upward pressure will also transmit through the boot to the surround and therefore any substantial forces will be more generally dissipated through first the parts of the user""s body in contact with the boot and also the protective surround.
In preference, the protective surround is tightly pulled and held with interlocking grip members so as to enable very tight close fitting engagement with the lower leg portion such as the calf and other parts of the lower leg of a user.
In preference, in relation to the substantially non-deformable sheet, there is a detonation material positioned on a lower face of this.
In explanation of this, there is now available material generally known as xe2x80x9cDETSHEETxe2x80x9d which is a detonation material which has the characteristics of detonating in the event of being subject itself to shock and pressure waves of the type first issued from an exploding landmine.
It has been discovered that by providing reactive shock and pressure waves in response to first shock and pressure waves which is primarily directed in an opposing direction to the first shock and pressure waves, has advantages in dissipating the first shock and pressure waves and to some extent, some following effects of the pressure wave.
Our proposal then is to provide for a detonation effect to be available to be triggered and arranged such that there will be a countering effect thus caused to an up-welling effect from an exploding landmine.
The substantially non-deformable sheet in preference substantially extends across the full sole area of the article of footwear.
In preference, the sheet is in the form of a metal plate of steel which for reasons of lightweight has ribs on a rear side both crosswise and longitudinally so as to provide for resistance against deformation about both longitudinal and transverse axes from an up-welling pressure wave.
In the item of footwear, there are further preferable features.
These include in the first instance a lowermost shape which comprises a plurality of open channels extending both longitudinal and transverse to allow for substantial venting through these.
The purpose of this arrangement is to allow for substantial venting in the first instance in the event of an exploding landmine.
Immediately above this lowermost sole portion in preference there is located above the substantially non-deformable sheet, at least one energy absorbing and dissipating barrier having a dissipatable material.
In preference then, there are a number of additional features including a lowermost frangible material and above this, in one case, a plurality of laminated sheets of kevlar impregnated fabric, and then above this, an open honeycomb structure.
For better understanding of the invention it will now be described with relation to a preferred embodiment, it being intended that the invention should not necessarily be limited to this.